A WGA device may have different traffic streams to another WGA device. For example, video traffic may require HDCP (High Definition Copy Protocol) encryption/decryption at the application layer, which is the upper layer of the MAC layer; this kind of traffic should not be encrypted in the MAC layer again. However, internet access may require MAC layer encryption/decryption.
To solve this problem, the WGA draft proposes to use the virtual MAC address method. A device has multiple STAs (stations). Each STA is identified by a MAC address. PCP (Personal Basic Set Control Point)/AP (Access Point) device can broadcast multiple BSSID (Basic Service Set Identifier) elements. Each BSSID identifies an PCP/AP. Different PCPs/APs can have different security capabilities: PCP/AP for video traffic indicates no MAC encryption/decryption capability, and PCP/AP for internet access indicates MAC encryption/decryption capability. Also, different STAs associate with different PCP/APs: STAs for video transmission associates with PCP/APs without encryption/decryption capability, and STAs for internet access associates with PCPs/APs with encryption/decryption capability.
There are many implications associated with virtual MAC addresses. There needs to be a separate security association for each STA that is identified by the virtual MAC address. It is required when L2 (Layer 2) security is expected, and it implies the establishment, termination, policies, keys, states, etc. for each STA (Station) that is identified by the virtual MAC instance. Also, beam training must be done for each STA that is identified by the association ID (AID)/MAC address explicitly as peer STAs) do not know the MAC addresses for the device. Therefore, there is redundancy in the case of multiple STAs that are identified by the virtual MACs within one physical device. This decreases protocol efficiency and increases power consumption. Further, SP allocation needs to be done for each STA that is identified by the AID separately, which is not optimal from a protocol efficiency or complexity perspective. Still further, to support multiple virtual MAC addresses adds implementation complexity, which is proportional to the number of virtual MACs to be supported simultaneously.
When two wireless devices other than WGA devices (e.g. 802.11 VHT devices) have multiple MAC address for some reason and need to communicate with other, they need to do beamforming two times for each pair of STAs that are identified by the MAC addresses. Also, other MAC layer redundancies exist. Such complexity should also be solved.
Therefore, there is a further need to support multiple MAC addresses in the art.